Postoperative infections with Clostridium perfringens are rare. We report a case of a 59-year-old male, admitted to our ICU for postoperative monitoring after an elective retroperitoneoscopic radical nephrectomy. This patient developed septic shock within 22 hours after laparoscopic surgery. Due to clinical deterioration, he was intubated and taken to the operating room, after a CT scan was performed. Surgery revealed an infected retroperitoneal haematoma, which was drained. Cultures identified C. perfringens as the causative pathogen. Postoperative C. perfringens infection is potentially life-threatening and rapid antibiotic treatment and surgical drainage play a pivotal role in its management.